Parameter specified as non-null is null error in Room Database

Issue

Here is my entity class:

@Entity
data class User(
    @PrimaryKey
    @Json(name = "id") val userId: String,
    @Json(name = "login") val userName: String,
    @Json(name = "avatar_url") val userAvatar: String,
    val profile: Profile? = null
) : Serializable

Here is my Profile data class

data class Profile(
    val avatar_url: String,
    val bio: String,
    val blog: String,
    val company: Any,
    val created_at: String,
    val email: Any,
    val events_url: String,
    val followers: Int,
    val followers_url: String,
    val following: Int,
    val following_url: String,
    val gists_url: String,
    val gravatar_id: String,
    val hireable: Boolean,
    val html_url: String,
    val id: Int,
    val location: String,
    val login: String,
    val name: String,
    val node_id: String,
    val organizations_url: String,
    val public_gists: Int,
    val public_repos: Int,
    val received_events_url: String,
    val repos_url: String,
    val site_admin: Boolean,
    val starred_url: String,
    val subscriptions_url: String,
    val twitter_username: Any,
    val type: String,
    val updated_at: String,
    val url: String
) : Serializable

but every time I try to insert data into the table I am getting the error, how can I insert null data object in table while using room database?

Solution

The issue here is that Room doesn't know how to insert attribute of type Profile to the table.

The simple solution would be to use a type converter. Something like the following:

class DatabaseConverters {
    @TypeConverter
    fun toProfile(profileJson: String): Profile? {
        return <Create a Profile object out of a JSON string>
    }

    @TypeConverter
    fun fromProfile(profile: Profile?): String {
        return <JSON string representation of Profile object>
    }
}

In your case - you can use "" (empty string) when Profile is null.

More info about converters: Here

Answered By - gioravered